Research dental consulting field

We are looking to do light research on the field of consultants serving the dental and orthodontic industry. We want to know the players, the market and demand for the whole dental and orthodontic consulting field. We have the types of consultants mapped, and we are in need of an overview of how big this field is, is it growing, how big are the companies on average, what are the primary arenas they focus on, what sort of products and services do they offer, etc.